The GFK mining throttle opening and closing state sensor, throttle switch sensor, throttle lockout 
 GFK (A) mine damper closed state sensor is supporting the use of "mine safe production monitoring system. The sensor can also be connected with other monitoring systems. It can continuously detect the throttle "switch" state set in the coal mine ventilation roadway. When the throttle due to various reasons is not strict, it can be issued by a switch signal to the computer monitoring system, so that the ventilation managers cry can accurately know the state of underground throttle switch. 
 Structure: 
 The instrument sensor head group and magnetic blocks of two parts constitute the sensor head (Figure 1) group composition of the shell of the reed switch, plug, plug cable fixing plate and other magnetic block group by Y25BH magnet shell 
 Principle 
 Reed switch in the magnetic field when the magnetic field strength reaches a certain strength, a group of contacts with the original pull the contacts disengaged, pull another contacts; when the reed switch from the strong magnetic field, but also to restore the original state . Using this principle, with the reed switch sensor head group and produce a strong magnetic field magnets are files in the edge of the damper door frames and doors (both relative) use of the throttle position changes, the instrument can produce switch signal, which is sent via cable to a computer monitoring system. 
 Technical features 
 Proof form: mining intrinsically safe; proof mark: ExibI 
 Output mode: switch output; output as a set of normally open contacts, capacity: 36V (AC) / 1A; 
 Working mode: continuous; measuring range: 0 ~ 40mm 
 Protective capacity of the IP54 level of GB4208 
 Dimensions: a sensor head assembly, mm: 110 × 60 × 35 
 b magnetic block components (mm): 80 × 40 × 25 
 The installation will install the sensor head groups on the door frame at the edge, then the magnetic block assembly in the Annex, with a fixed throttle edge of the sensor head group at the corresponding. 
 Connection available to the user terminal box and the instrument itself with a good cable to "KJPF the mine safe production monitoring system" underground sub-station wiring. 
 Adjustments for: throttle switch is installed, the throttle in the account status, throttle and doorframe gap distance of the alarm user's own regulations, then the user can within a certain range selected alarm distance. Determined by the initial position of the sensor head group and the magnet group, so the user can guarantee the normal work of the instrument depending on the circumstances flexible installation.